**Core Concept**
Choroidal neovascularization (CNV) refers to the growth of new blood vessels in the choroid layer of the eye, often associated with age-related macular degeneration (AMD) or other ocular diseases. This phenomenon is a key feature of various retinal disorders, leading to vision loss due to fluid leakage, hemorrhage, and scarring.

**Why the Correct Answer is Right**
Choroidal neovascularization is characterized by the formation of new blood vessels in the choroid, which is a layer of blood vessels between the sclera and retina. This process is mediated by angiogenic factors, such as vascular endothelial growth factor (VEGF), which promotes the proliferation and migration of endothelial cells. In diseases like AMD, CNV is thought to result from chronic inflammation and oxidative stress, leading to the breakdown of the blood-retinal barrier and subsequent neovascularization.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because CNV is not typically associated with optic neuritis. Optic neuritis is an inflammatory condition affecting the optic nerve, rather than the choroid layer.

**Option B:** This option is incorrect because diabetic retinopathy primarily involves the formation of microaneurysms, retinal hemorrhages, and hard exudates, rather than choroidal neovascularization.

**Option C:** This option is incorrect because retinal detachment is a condition where the retina separates from the underlying retinal pigment epithelium, often due to trauma or retinopathy, but it is not characterized by choroidal neovascularization.

**Option D:** This option is incorrect because epiretinal membrane formation involves the deposition of fibrocellular tissue on the surface of the retina, often leading to visual distortion and metamorphopsia, but it is not directly related to choroidal neovascularization.

**Clinical Pearl / High-Yield Fact**
Choroidal neovascularization is a significant risk factor for vision loss in age-related macular degeneration, and anti-VEGF therapies have become a cornerstone in managing this condition.

**Correct Answer:** D.